Rabies has been found to exist as a latent infection of rodents in Europe. A search for latent rabies infections in small rodents and insectivores was initiated in Iowa. Serial passage of brain, salivary gland and brown fat in mice and tissue culture is being used to search for rabies isolates. Virus isolations have been made from approximately 15% of the animals but none of these have been identified as rabies to date. Standard physical-chemical procedures are being used to identify these isolates. Fluorescent antibody procedures with frozen sections of naturally infected skunks show that neuroepithelial tissues of the nasal cavity, buccal surfaces and tongue are heavily infected with rabies virus and may constitute an additional source of rabies virus in its natural spread. A pen study of latent rabies infections in skunks has also been initiated. Skunks are being captured and descented. Serum and cerebral spinal fluid samples are taken for neutralizing antibody. Corticosteroids will be used in an attempt to exacerbate any latent rabies infections after an appropriate holding period. Additional experimental challenge will also be carried out late in the holding period.